FUNCTIONAL FOODS

Britt MacArthur, Katherine Mykytka,

Rebecca Dover, Kerri Kimzey, & Jessica

Oakley

What is a functional food?

Functional Foods

•

Functional foods are foods that contain

additional benefits which exceed their basic

nutritional value

•

A functional food should be nutritious before

additional supplements are added.

•

Today they include a wide range of items

including whole grains, fruits, fatty fish, and

foods or beverages that have been fortified or

enhanced

History

•

Over two thousand years ago Hippocrates said, "Let
food be thy medicine." Although the concept of
functional foods is not entirely new, it has evolved
considerably over the years.

•

The basis for the progression of interest in functional
foods can be found all the back in the 1920s when
iodine began being added to salt to prevent goiters.

History

•

Other twentieth-century examples include vitamin A

and D fortification of milk and niacin and folic acid

fortification of grains.

•

These early fortification examples focused on

reducing the risk of diseases of deficiency. In the

latter part of the twentieth century, consumers began

to focus on wellness and the reduction of chronic

disease.

•

Research now focuses frequently on the promotion of

health through many lifestyle factors, including the

consumption of an optimal diet.

•

As of 2002, researchers have identified hundreds of

food components with functional qualities, and they

continue to make new discoveries surrounding the

complex benefits of phytochemicals in foods.

Credibility

•

American Dietetic Association position
statement
-The American Dietetic Association made a
statement earlier this year about their position
on the issue. They gave their support for the
usage of functional foods and for research into
advancing the field and furthering the benefits
of their incorporation into a balanced, varied
diet for all individuals.

Rationale and Regulation

•

Consumer demand has increased development of functional
foods, due in part to:
-Increased health care costs, an awareness and desire to
enhance personal health, advancing scientific evidence that
diet can alter disease prevalence and progression, aging
population, and changes in food regulation

•

The Food and Drug Administration- regulation

Categories

•

Conventional/Unmodified whole foods such as
fruits and vegetables: represent the simplest
form of a functional food
Ex. Carrots are considered to be functional
foods because they are rich in such
physiologically active components such as beta
carotene

•

Modified foods (fortified and enhanced foods) are
also considered to be functional

FRUITS &
VEGETABLES

Fruits & Vegetables

•

the simplest form of functional foods

•

A natural form

•

One of best sources for antioxidants and
phytochemicals

Why are fruits & vegetables
necessary?

•

oxidation= the loss of an electron

•

Produces reactive substances known as free

radicals that cause damage to cells

•

Caused by: normally during metabolism, body’s

immune system purposefully creates them to

neutralize viruses and bacteria, & environmental

factors such as pollution, radiation, cigarette

smoke and herbicides

•

Natural process in the body

•

Causes degenerative diseases associated with

aging and cancer

WHAT ARE
ANTIOXIDANTS?

Antioxidants

•

Natural components present in fruits and
vegetables

•

Stabilizes free radicals before they cause harm

•

Present in vitamins, minerals, carotenoids, and
polyphenols

•

Due to the naturally occurring process of
oxidation, we must have a balance of
antioxidants to maintain health

Phytochemicals

•

One type of antioxidants

•

Promote optimal health by lowering
risk for chronic diseases

•

Only found in plant foods

•

Fruits and vegetables are best
sources

EXAMPLES OF
FUNCTIONAL
COMPONENTS

Carotenoids

•

Beta-carotene

–

Sources: carrots, various fruits, sweet potatoes,

leafy green vegetables, red peppers, & pumpkin

–

Specifically reduces risk for lung cancer

•

Lutein & Zeaxanthin

–

Sources: kale, collards, spinach, corn, & citrus

–

Reduces risk of cancer & promotes eye health

(specifically macular degeneration)

•

Lycopene

–

Sources: tomatoes

–

Reduces risk of prostate cancer

Flavonoids

•

Anthocyanidins

–

Sources: berries, cherries, red grapes

–

Contributes to maintenance of brain function

•

Flavanols

–

Sources: apples, grapes

–

Contributes to maintenance of heart health

•

Flavanones

–

Sources: citrus foods

–

Reduces risk of cancer

More flavonoids

•

Flavonols

•

Sources: onions, apples, broccoli

•

Reduces risk of cancer

•

Proanthocyanidins

•

Sources: cranberries, apples, strawberries,
grapes

•

Promotes urinary tract health and heart
health

Isothiocyanates

•

Sulforaphane

•

Sources: cauliflower, broccoli, Brussels
sprouts, cabbage, kale, horseradish, turnips

•

Reduces risk of cancer

Phenols

•

Caffeic acid/ Ferulic acid

•

Sources: apples, pears, citrus fruits,
some vegetables

•

Promotes healthy vision and heart
health

Plant Stanols/Sterols

•

Free stanols/sterols

•

Sources: corn

•

May reduce risk of Coronary Heart
Disease

Prebiotic/Probiotics

•

Inulin, Fructo-oligosaccharides,
Polydextrose

•

Sources: onions, some fruits, garlic,
leeks

•

Improves gastrointestinal health
and calcium absorption

Phytoestrogens

•

Lignans

•

Sources: some vegetables

•

Promotes heart health and healthy
immune function

•

Reduces risk of breast cancer

Sulfides/Thiols

•

Diallyl sulfide, allyl methyl trisulfide

–

Sources: garlic, onions, leeks, scallions

–

Promotes heart health and healthy immune
function

•

Dithiolthiones

–

Sources: broccoli, cauliflower, Brussels
sprouts, cabbage, turnips

–

Promotes healthy immune function

–

Detoxifies carcinogens

WHAT % OF AMERICANS
DO NOT EAT
VEGETABLES AT ALL?

50%

Statistics

•

Less than 10% of Americans eat 2
servings of fruit and 3 servings of
vegetables each day

•

Over 70% eat no fruits or vegetables rich
in Vitamin C per day

•

80% eat no fruits or vegetables rich in
carotenoids per day

Recommendations

•

3-5 servings of vegetables
everyday

•

2-4 servings of fruits everyday

PLANT STEROLS AND
STANOLS, OMEGA-3
FATTY ACIDS AND SOY
PROTEIN

Functional foods and drinks are products that have been

enriched with added nutrients or other substances that are

considered to have a positive influence on health. Examples

include cholesterol lowering spreads and foods with added

nutrients, such as plant sterols and stanols, omega-3 fatty

acids, and soy proteins. Lets take a look at the more popular

functional foods currently on the market, and see how they

may benefit our health and the evidence behind some of the

claims being made about them.

Plant stanols and sterols

•

Plant stanols and sterols are plant-derived lipids

which are of particular interest because of their

potential health benefits, particularly in relation to

cardiovascular disease (CVD).

•

Sterols are essential components of plant cell

membranes and play a key role in controlling

membrane fluidity and permeability.

•

Stanols are saturated sterols and occur naturally in

small amounts in plant products such as nuts,

seeds and legumes.

Plant stanols and sterols

•

Both plant stanols and sterols have a structure that

is very similar to cholesterol.

•

They have been incorporated into many food

products, most notably fat spreads, otherwise

known as ‘cholesterol-lowering spreads’.

•

Studies have found that consuming approximately

2g of plant stanols or sterols each day leads to a

significant reduction in cholesterol concentrations

in people with elevated cholesterol levels.

•

Found to lower total and low density lipoprotein

(LDL) cholesterol, without affecting high density

lipoprotein (HDL); therefore thought to be effective

in reducing the risk of heart disease

Plant stanols and sterols

•

It is not possible to acquire their benefits by consuming

plant foods alone. Products with added plant stanols and

sterols need to be consumed in order to obtain their

benefits.

•

Studies have shown that these products also have the

potential to significantly reduce both total and LDL

cholesterol when consumed regularly with meals.

•

Studies have also shown that the cholesterol lowering

benefits of plant stanols and sterols are independent of

diet, and greater cholesterol reductions can be achieved

by following an overall healthy diet, exercising, and

reducing saturated fat intake, while in addition to

consuming products containing plant stanols and sterols

(Andersson et al, 1999).

Plant stanols and sterols

•

Although plant stanols and sterols have been shown to effectively

reduce cholesterol concentrations at an intake of 2g per day.

•

There is currently no direct evidence that they actually reduce the

incidence of CVD events (i.e. heart disease and stroke)

More trials are required to determine the effectiveness of

plant stanols and sterols and their affect on CVD events.

•

The use of foods with added plant stanols and sterols is also of

questionable benefit in individuals who do not suffer from elevated

cholesterol.

•

However, the consumption of such products (including cholesterol-

lowering spreads, yogurts and other drinks) as part of an otherwise

healthy diet, has been shown to be a promising addition, as intervention,

for heart disease prevention.

Products with added
omega-3

•

Omega-3 fatty acids are a type of

polyunsaturated fatty acid.

•

Certain omega-3 fatty acids are termed

‘essential’ because they cannot be made in the

body and therefore have to be provided by the

diet.

Omega-3 Fatty Acids

•

There has been considerable interest in the long-chain

omega-3 fatty acids, eicosapentaenoic acid (EPA)

•

Docosahexaenoic acid (DHA)

Omega-3 Fatty Acids

Which are derived from alpha-linolenic acid

(ALA)

However, the conversion of ALA to the longer-chain omega-3

fatty acids-EPA and DHA- is considered to be very limited
in humans, so additional dietary sources are needed.



Omega-3 Fatty Acids

•

The interest steamed from a study done in the late 1970s on the

Greenland Inuits. The study showed a low occurrence of coronary

heart disease (CHD) in this Eskimo population which was attributed

to their traditional diet of marine plants and animals particularly

oily, fatty fish.

•

All sources rich in omega-3 fatty acids EPA and DHA.

•

The best dietary source of EPA and DHA is oily, fatty fish, but now

there are increasing numbers of products on the market that have

been fortified with EPA and DHA, such as eggs, bread, milk, and

dairy products.

Health Effects of Omega-3
FA

•

The cardiovascular benefits from long chain omega-3

fatty acid consumption have been attributed to their

anti-inflammatory and anti-clotting effects.

•

Consumption of fish, particularly fatty fish, offers

significant health benefits in terms of a reduction in

the risk of CVD.

•

Moderate fish consumption and fish oil supplementation

raised blood levels of DHA and slowed down the progression

of abnormal thickening of artery walls due to fatty deposits

(a condition that restricts blood flow to the heart, called

atherosclerosis).

Omega-3 and Cognitive
Function



There has recently been a lot of speculation,
particularly in the media, that omega-3 fatty
acids may influence cognitive function and
behavior, particularly in children. However,
research in this area is still in its early stages,
and so far there is little evidence that
supplementation with omega-3 fatty acids, in the
form of fish oils, leads to improvements in
cognitive function (Lunn and Theobald, 2006).

Omega-3 Fatty Acids

•

While the benefits of including fish, particularly oily fish, in the

diet are well recognized, many people do not eat oily fish

regularly and, therefore, it is important to eat other dietary

sources of omega-3 fats.

•

There are a wide range of products with added omega-3

currently on the market but it is important to consider their

efficacy.

•

For example, it is important to take into account whether products

actually provide the long-chain omega-3 fatty acids (EPA and DHA)

or simply the shorter-chain omega-3 fatty acid, ALA.

•

The amount of omega-3 provided is also an important factor: as

a benchmark, an intake of two portions of fish per week,

including one oily, is equivalent to 450mg per day of omega-3

fatty acids.

Soy Protein

•

Another major interest for atherosclerosis
prevention has been addressed to vegetable
proteins, particularly soy proteins whose
consumption has been shown to successfully
reduce cholesterolemia in experimental animals,
as well as in humans with cholesterol elevations
of genetic or non genetic origin.

Soy Protein

One study addresses the potential of soy protein to increase

low-density lipoproteins receptors (LDL-R) expression in

human beings.

Procedure: Compared two groups

Group One: Patients were treated with animal protein
Group Two: Patients were treated with textured soy protein

(with the addition of cholesterol to balance the two diets)

Results:

Group One:

•

After the animal protein diet there were minimal changes in low-

density lipoprotein cholesterol (LDL-C) levels or LDL-R activity,

Group Two:

•

The soy protein diet, in addition to a LDL-C reduction, showed an ↑ of

around eightfold in total LDL degradation. This study, clearly suggests

that some soy protein components are able to up-regulate LDL-R,

decrease LDL-C, resulting in total LDL degradation.

Soy Protein

•

A full understanding of the mechanism of action of soy

protein has become vital for the selection of the most

appropriate forms of soy for treating hypercholesterolemia

(

high blood cholesterol and triglycerides)

•

This selection can only be made once the active

component/s and their mechanism of action have been

fully revealed

•

So what’s in Soy Protein or rather soybeans?

•

The major storage proteins in soybeans are 7S and 11S

globulins: from early studies the 7S globlin appear to be

primarily responsible for the hypocholesterolemic effects of

soy protein, whereas the 11S component appeared

essentially inactive.

Soy Protein

An interesting activity on hypercholesterolemia and body weight was

conducted

Procedure:

Gave a daily administration of four candies containing 5 g of 7S globulin

to moderately overweight Japanese individuals with

hypercholesterolemia

Results:

↓ TGs by 14%
↑raised HDL-C by 5%

Exerted a remarkable 6% reduction in the mean visceral fat area.

Proving:

The remarkable effectiveness of this very simple regimen thus

reinforces the recommendation to increase the intake of soy proteins

for cardiovascular protection.

CARBOHYDRATES

Dietary Fibers

•

Dietary fibers refer to the remains of
plant cells that are resistant to
hydrolysis by human enzymes

•

Positive influence on constipation,
hyperlipidemias, diabetes, obesity, and
diverticular disease

Dietary Fibers

•

Many different kinds:

–

General dietary fibers

•

Carbohydrate and lipid metabolism modulation,

antioxidants, phytonutrients

–

Insoluble fiber

•

Aid to digestion, promote regularity, prevent constipation

–

Soluble fiber

•

Protective benefits

–

Viscous polysaccharides

•

Cholesterol lowering

–

Intermediate fibers

•

Prebiotic effect, cholesterol lowering

–

Resistant starch

•

Bowel function